Thread rolling machine for manufacturing a particular type of rolled thread

ABSTRACT

Thread rolling machine for manufacturing a rolled thread characterized by a pair of external threads formed upon a thread shaft at both end portions thereof and a pair of stopper grooves formed upon the thread shaft at adjacent inside positions of the respective external threads.

Umted States Patent 1 1 3,691,806

Hanzawa [451 Sept. 19, 1972 [54] THREAD ROLLING MACHINE FOR 1,609,422 12/1926 Olofson ..72/92 MANUFACTURING A PARTICULAR 2,109,918 3/1938 Friedman ..10/165 Y OF ROLLED THREAD 2,180,555 1 H1939 Sipe ..72/93 2,283,494 5/1942 Erdman ..10/27 [721 Yam Ham, Tokyo Japan 2,591,285 4/1952 Overly ..10/165 73 Assi okabe Com an T k 2,870,663 1/1959 Hubl ..10/165 1 g Japan p y 0 yo 2,923,186 2/1960 Pierson ..72/92 3,204,442 9/1965 Wieber ..72/88 [22] Filed: Oct. 22, 1970 2,356,686 8/1944 Newall ..10/27 [21] Appl' 82938 Primary Examiner-Charles W. Lanham Assistant ExaminerE. M. Combs 30 Foreign Application Priority Data ArwrneyM1lI9n J Wayne Nov. 6, 1969 Japan ..44/105380 57 ABSTRACT I Thread rolling machine for manufacturing. a rolled 2? 2 52 35 thread characterized by a pair of external threads 1 g I i formed upon a thread shaft at both end portions [58] Fleld of Search ..10/2, 27, 152, 153, 165; thereof and a pair of stopper grooves formed upon the 72/88, 91, 92, 93, 469 thread shaft at adjacent inside positions of the respective external threads. [56] References Cited 3 Claims, 11 Drawing Flgures UNITED STATES PATENTS 780,527 1/1 905 Replogle et a1 ..72/93 PATENTEDSEP 19 m2 SHEET 1 BF 7 INVENTOR BY hux Q 4 ATTORNEY PATENTEI] SEP 19 1972 SHEET 2 OF 7 PATENTEDSEP 19 I972 SHEET 5 0F 7 F/g. 9A

I INVENTOR ATTORNEY PATENTEDSEP 19 I972 3.691. 806

sum 6 or 7 INVENTOR ATTORNEY PATENTED SEP 19 I972 sum 7 or I INVENTOR BY Ark Q ATTORNEY THREAD ROLLING MACHINE FOR MANUFACTURING A PARTICULAR TYPE OF ROLLED THREAD BRIEF SUMMARY OF THE INVENTION The present invention relates to a thread rolling machine, more particularly relates to a thread rolling machine for continuously and automatically manufacturing rolled threads, each rolled thread. is provided with a pair of external threads formed upon a thread shaft at both end portions thereof and a pair of stopper grooves formed upon the thread shaft at adjacent inside positions of the respective external threads.

The above-mentioned rolled-thread, that is, the rolled thread characterized by a pair of external threads formed upon a thread shaft at both end portions thereof and a pair of stopper grooves formed upon the thread shaft at adjacent inside positions of the respective external threads, was developed by the present applicant to be utilized as an auxiliary material in the process of the concrete construction. However, at least two steps of machine operation to produce the above-mentioned rolled thread was required.

It is the principal object of the present invention to provide an exclusive thread rolling machine for manufacturing the above-mentioned particular type of rolled threads automatically and continuously by one step, so that the production cost can remarkably be reduced.

The exclusive thread rolling machine of the present invention is characterized by a pair of thread rolling cylindrical dies mounted on a rotation shaft at both end portions thereof with a predetermined axial distance and a pair of thread rolling flat dies stationarily disposed to the machine so that each flat die faces the respective cylindrical die with a predetermined intervened space, and a pair of dies which is provided with a single projected thread having a thread-line perpendicularly formed to an axis of the rotation shaft disposed to the machine at the adjacent inside positions of the thread rolling flat dies, respectively. Each material rod is successively fed to the intervened space between the threadrolling cylindrical dies and the respective thread rolling flatdies while the thread rolling cylindrical dies are rotating with the rotation shaft. Therefore, the material rod is turned and a pair of external threads and a pair of stopper grooves are plastically made while passing through the respective intervened spaces.

Further features and advantages of the invention will be apparent from the ensuing description with reference to the accompanying drawings to which the scope of the invention is in no way limited.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING FIG. 1 is a schematic elevation of the main part of the thread rolling machine according to the present invention,

FIG. 2 is a schematic side view, partly in section, of the main part of the thread roiling machine, shown in FIG. 1,

FIG. 3 is an explanatory view for illustrating the characteristic feature of the thread rolling machine, according to the present invention,

FIGS. 4 and 5 are schematic front views of the thread rolling cylindrical die and the thread rolling flat die utilized for the machine shown in FIG. 1,

FIG. 6 is a side view of the die for forming a stopper groove upon the shaft of the external thread, utilized for the machine shown in FIG. 1,

FIG. 7 is a front view of a practical thread rolling machine according to the present invention,

FIG. 8 is a cross-sectional view, partly omitted, of the main part of the thread rolling machine, taken along line IIX IIX in FIG. 7,

FIGS. 9A, 9B and 9C are explanatory drawings for illustrating the motion of the stop means of the thread rolling machine shown in FIG. 7.

DETAILED DESCRIPTION For the convenience of the illustration of the thread rolling machine of the present invention, the principle of the machine of the present invention is firstly explained.

Referring to the drawings showing an embodiment of the present invention, the exclusive thread rolling machine of the invention is provided with a supporting frame 1 and a pair of bearings 2 mounted upon the supporting frame 1 at both end portions thereof and a rotation shaft 3 rotatably supported by the bearings 2. A pair of thread rolling cylindrical dies 4 are coaxially secured to the rotation shaft 3 by respective keys with a predetermined axial intervened distance. These cylindrical dies 4 are the same size and are provided with the same threads formed upon the circumferential surfaces thereof. A pair of thread rolling flat dies 5 are stationarily mounted upon the supporting frame 1 so that each flat die 5 faces each part of the cylindrical dies 4 with a predetermined intervened space. Therefore, the thread rolling operation can be carried out in a uniform and steady condition. It is important that the inside surfaceof each flat die 5 forms a portion of a cylindrical surface which has coaxial relation with the cylindrical outer surface of the cylindrical die 4 and this inside surface is provided with threads which correspond to the threads formed upon the cylindrical surface of the cylindrical die 4. Therefore, the pitch, screw-thread and helix angle of these threads of the cylindrical dies and flat dies correspond to each other. A pair of'auxiliary dies 6 are stationarily mounted upon the machine frame 1 at the adjacent inside positions to the respective flat dies 5 as sown in FIG. 1. Each of the dies 6 is provided with a projected thread 7. Each inside surface of the dies 6 forms a portion of a cylindrical surface which is coaxial with the circumferential surface of the cylindrical die 4. The thread line of the projected thread 7 is perpendicular to the axial line of the rotation shaft 3. As is shown in FIG. 6, the starting portion 7a and the terminal portion 7b of the projected thread 7 is gradually cut-off so that the feeding of the material rod and the discharging of the products can be carried out smoothly. As mentioned above, when these component elements are assembled at their predetermined position, an intervened space having a circular arc is formed between each cylindrical die 4 and the facing flat die 5 and die 6.

Referring to FIG. 2, a hopper 9 for receiving a plurality of metallic material rods 13 is disposed above the entrance of space 8 formed between dies 4 and 5, and a supply chute 10 is connected to a bottom aperture of the hopper 9. Therefore, a vertically disposed bottom aperture of the chute 10 faces the entrance to space 8. A pawl wheel mechanism 11 is disposed at an adjacent 10. A stop means 12 is disposed with respect to a bottomportion of the chute so as to feed the material rods 13 into the space 8 one by one. The stop 12 comprises a pair of plates 12a, 12b which alternately close the passages ofthe chute 10. The distance between the closing positions of these plates 12a, 12b is so determined that .one material rod 13 can be housed withinv the space defined chute 10. a

The-process for manufacturing the rolled threads by the above-mentioned thread rolling machine is hereinafter illustrated. After starting the rotation of the, rotating shaft 3 in a clockwise direction, as shown by an arrowin FIG. 2, the stopnmeans l2 is driven 'together with the pawl-wheel mechanism II by a drive means (not shown) so that vibration of the'material rods 13 in the hopper 9 is created and the material rods 13 are fed into the chute 10 successively. While the stop means l2 is operating, the material rods 13 can be fed to the entrance of the space 8 one by one. The time interval of feeding the successive material rods-l3 can be adjusted by changing thespeed of the opening and closing motions of the plates 12a, '1 2h. When the material rods 13 are fed to the space 8 and contact the threads of the cylindrical dies 4 andthe flat dies 5 the rods l3 are caused m rot ale counterclockwise as shown by the arrow and symbol V"/ in'FlG. 2 and are displaced to the terminal end of the space 8. Since the space distance between the screw threads of the cylindrical die 4 and the flat die 5 isso set that the diameter of the thread groove of the external threadformed upon the material rod' 13 is equivalent to the space distance while the space distance between the thread grooves of the cylindrical die 4 and the flat die 5 is equivalent to the diameter of -the screw thread formed upon the material rod 13, the outer layer of the rod' 13 is plastically deformed so as to precisely engage with the rotating cylindrical thread of thecylindrical die 4 and the threads of the flat die 5, as is well-known, is the art of the conventional thread rolling. Therefore, when the by these plates 12a, 12b and the rod 13 is discharged from the-space 8, a pair of external threads 14 are formed upon both end portions of the rod 13. Since a pair of dies 6 are disposed at adjacent inside portions of the flat dies 5 and when the rod 13 is subjected to be displaced to the terminal end of the space 8 while 'the outer layer thereof is plastically deformed, each contact portion of therod 1.3 with the single thread 7 of the die 6 is also plastically deformed so that pair of annular stopper grooves 15 are formed upon the rod 13 at adjacent inside'portions of each ex- In accordance with a desired intervened length between two external threads'formed on each rod, a-

setting position of inside cylindrical die 4 upon the shaft 3 at the left side in FIG. 7 is firstly adjusted by changing numbers of divided colors 18 which are disposed upon the shaft 3 man intervened position between two cylindrical dies 4, and then the position of this die 4 is secured upon the shaft 3 with a plurality of lock nuts 19. The cylindrical die 4 and the flat die 5 at the right side in FIG. 7 are positioned facing each other (the die 5 is not shown in FIG. 7, but is at the back side of the right side supporting frame and the right side cylindrical die 4 in FIG. 7). The supporting frame 1, which supports the flatdie Sat the right side in FIG. 7, is secured upon the horizontal upper surface of the base frame 20 so that the flat'die 5 faces the right'side cylindrical die 4 in FIG. 7. Next, a setting position of the supporting frame 1 of the left side is adjusted. This adjustment is firstly to loosen fasteners la which fix the frame 1 upon the machine base 20 and then turn a handle 17b secured to a free end of an adjusting shaft 17 having a threaded end portion 17a whichengages a threaded aperture formed at a bottom portion of the frame 1 and after confirmation of the intervened distance between the supporting frames so as to fit a desired length, the left side frame I. is secured to the base frame 20 by fastening the fasteners la. y

The shaft 3 is driven by the drive motor 21 by way of a motorshaft 21a and a pulley 22 secured on the shaft 21a and a belt 23 and another pulley 3a secured on an end of the shaft 3. The shaft 3 is rotatably supported by a pair of stationary hearings 2a and 2b and a slidable bearing 34 mounted upon the horizontal upper surface of the base frame .20.

The practical mechanism of the stop means for regulating the supply of the material rods 13 into the machine, is shown in FIGS. 7 and 8. The material rods 13 are received in the hopper 9 and the rods 13 are sup plied to the thread rolling mechanism one by one through a chute 10. A pair of stop means 27a and 27b are mounted on the a respective supporting frames '1. Each stop mans comprises a swing lever 24 secured on a horizontal shaft 25 swingably'supported by the supporting frame 1. A plate.l2ais connected to the lever 24 by way of a connecting member 29, and another plate 12b is movably supported by a slide member 31 slidably held by a cylindrical case 30 wherein a helical spring 32 is held so that .the slide member 31 is always urged toward an entrance space between the cylindrical die 4 and the flat die 5. A stopper 30a is formed at a lower end of the cylindrical case 30 so as to restrict the lower most position of the plate 12b. A cam shaft 27 is rotatably supported by the right side supporting frame I and driven by a gear train 35 rotatably mounted on the right side bearing 34!). The gear train '35 is driven by the rotation of the shaft 3. A cam 28 is rigidly mounted on the shaft 27 and always contacts a cam ball 26 which is rotatably mounted on the right side swing lever 24. Therefore, the swing lever 24 of each stop means swings about the shaft 25 in accordance with the rotation of the cam 28. A guide member 29a is secured on the supporting frame 1 so that the plate 12a is reciprocally moved therethrough.

Referring to FIGS. 9A, 9B and 9C, at the starting positions (FIG. 9A) of the plates 12a, 12b, a first material rod A0 is fed into a space 8a defined by the cylindrical die 4, the chute l0 and the plates 12a, 12b. As shown the plate 12b initially prevents supplying of the rod A0 into the working space 8 defined by the cylindrical die 4 and the flat die 5. This rod is represented by Al. When the plate 12a is further advanced (FIG.9B), the rod Al pushes the tip of the plate 12b so that the plate 12b is retracted and the rod Al is pushed into the space 8' (FIG. 9B), while supplying a second fresh rod A0 intothe space 8a is prevented by means of closing the opening of the chute 10 by the plate 12a. Next, the plate 12a is retracted to the first position in accordance with the cam motion so that the chute 10 is opened, the plate 12b is simultaneously displaced to its lower most position so that the second fresh rod A0 is led into the space 8a and the tip of the plate 12b prevents the feeding of the second fresh rod A0 into the space 8. The first fresh rod A0 fed into the space 8 is then being subjected to the thread rolling operation as already described so that product A2 is discharged from the outlet of the space 8. The abovementioned operation is carried out intermittently. The pawl wheel mechanism 11 comprises a plurality of pawl wheels 11 a mounted on a shaft 11b rotatably supported by a pair of bearings secured to the hopper 9 so that each pawl is projected through a window 9a formed upon a bottom of'said hopper. The shaft 11b is driven by the shaft 3 by way of a chain drive mechanism comprising a sprocket wheel 3!) mounted on the shaft 3 and a sprocket wheel 1 1c mounted on the shaft 11b and an endless chain connected these sprocket wheels 3b and 110. Pawls of the pawl wheel 1l control the supply of the fresh rods A0 from the hopper 9 into the chute 10 so as to feed the rods A0 one by one. As mentioned above, since the material rods A0 are fed to an entrance portion of the thread rolling mechanism of the invention and the products A2 are discharged from the delivery side of the mechanism, the operation of this machine can be continuously carried out with very high efficiency.

As mentioned above, the exclusive thread rolling machine according to the present invention has excellent functions for producing the rolled thread comprising a shaft and a pair of external threads formed upon both sides of the shaft with a predetermined axial distance and a pair of annular stop grooves formed at adjacent inside positions of each external thread by one process with easy and precise operation thereof so that a great deal of manual operation can be eliminated. It is very important that the machine efficiency and precision of the threads, according to the present invention, are very high. Consequently, the rolled thread provided with a pair of external threads and annular grooves having uniform quality can be produced economically.

I claim:

l. A thread rolling machine for cutting a pair of external thread portions on the end areas of rods comprising a main shaft;

a pair of cylindrical dies spaced from each other and mounted to rotate on said main shaft;

a pair of fixed semi-circular dies positioned in corresponding relation to said cylindrical dies to provide a predetermined semi-circular space therebetween to receive the rods seriatim for the thread cutting; said fixed dies emg horizontally spaced from said main shaft and providing an entrance area to said space located above said cylindrical dies and further providing an exit area from said space located below said cylindrical dies, said entrance and exit areas being in substantial vertical alignment; A

a pair of auxiliary dies respectively located adjacent said fixed dies on the inside thereof for cutting respective stopper grooves in the rodsadjacent the thread portions;

hopper supply means for the rods located above said dies and having a first outlet opening vertically spaced above said entrance area;

a hollow chute connected to said first outlet opening and extending substantially vertically downward to terminate in a second outlet opening adjacent said entrance area, said pair of outlet openings being in substantial vertical alignment with said entrance and exit areas;

a second shaft spaced vertically above said main shaft and adjacent a bottom area of said hopper supply means;

a pawl wheel mounted to rotate on said second shaft, part of said pawl wheel extending into said hopper supply means to contact the rods therein to aid in feeding the rods into said chute; and

a pair of shutter plates each having ends slidable within said entrance area, one shutter plate disposed to slide radially with respect to said main shaft, and the other shutter blade disposed to slide tangentially with respect to said main shaft, with means being provided to operate said shutter plates intermittently to individually feed the rods from said chute into said space for simultaneously cutting threads on a plurality of the rods.

2. A machine according to claim 1 in which said radially slidable shutter plate is positioned on one side of said substantially vertically extending chute and has an acute angular relationship therewith, the end of said radially slidable shutter blade being normally biased to extend into and close said entrance area to the reception of the rods.

3. A machine according to claim 2 in which said tangentially slidable shutter plate is positioned on the other side of said substantially vertically extending chute and has an acute angular relation therewith, and said operating means being provided by a cam to effect the intermittent operation of said tangentially slidable shutter plate which is extended into said entrance area UNiTED "STATES PATENT swim QER'HFICATE @F QQRREQTEQN Patent No. 3, 91, 0 Dated September l9 .l9 2

Inv n r( Yasuo Hanzawa It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 4 "sown" should be -shown.

Column 4, line 38: "9" should be --9- Column 5, line's25 and 34: "9" should be 9'- Column 4, line 40: "-10" should be lO'-- I Column 5, lines 2, 1]., l4 and 34: "10" should be -lO- Column 4, lines 44 and 65: "12a" should be l2a'- Column 5, lines 2, 6 and 12 12a" should be l2a'-- Column 4, lines 46 and 65: "12b" should be -l2b'- Column 5, lines 2, 3, 8 (two occurrences) l4 and 17: "12b" should be l2b' Signed and sealed this 29th day of May 1973.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioneiof Patents FORM P0-10 (1 USCOMM-DC scam-ps9 U.5. GOVERNMENT PRINTING OFFICE: i969 O-366-334 

1. A thread rolling machine for cutting a pair of external thread portions on the end areas of rods comprising a main shaft; a pair of cylindrical dies spaced from each other and mounted to rotate on said main shaft; a pair of fixed semi-circular dies positioned in corresponding relation to said cylindrical dies to provide a predetermined semi-circular space therebetween to receive the rods seriatim for the thread cutting; said fixed dies being horizontally spaced from said main shaft and providing an entrance area to said space located above said cylindrical dies and further providing an exit area from said space located below said cylindrical dies, said entrance and exit areas being in substantial vertical alignment; a pair of auxiliary dies respectively located adjacent said fixed dies on the inside thereof for cutting respective stopper grooves in the rods adjacent the thread portions; hopper supply means for the rods located above said dies and having a first outlet opening vertically spaced above said entrance area; a hollow chute connected to said first outlet opening and extending substantially vertically downward to terminate in a second outlet opening adjacent said entrance area, said pair of outlet openings being in substantial vertical alignment with said entrance and exit areas; a second shaft spaced vertically above said main shaft and adjacent a bottom area of said hopper supply means; a pawl wheel mounted to rotate on said second shaft, part of said pawl wheel extending into said hopper supply means to contact the rods therein to aid in feeding the rods into said chute; and a pair of shutter plates each having ends slidable within said entrance area, one shutter plate disposed to slide radially with respect to said main shaft, and the other shutter blade disposed to slide tangentially with respect to said main shaft, with means being provided to operate said shutter plates intermittently to individually feed the rods from said chute into said space for simultaneously cutting threads on a plurality of the rods.
 2. A machine according to claim 1 in which said radially slidable shutter plate is positioned on one side of said substantially vertically extending chute and has an acute angular relationship therewith, the end of said radially slidable shutter Blade being normally biased to extend into and close said entrance area to the reception of the rods.
 3. A machine according to claim 2 in which said tangentially slidable shutter plate is positioned on the other side of said substantially vertically extending chute and has an acute angular relation therewith, and said operating means being provided by a cam to effect the intermittent operation of said tangentially slidable shutter plate which is extended into said entrance area thereby contacting and pushing an individual rod into said space as it simultaneously forces the retraction of said radially slidable shutter plate against its bias to open said entrance area. 